Publications by authors named "Hallam D"

Article Synopsis
  • Biallelic mutations in the DRAM2 gene cause a form of vision loss called CORD21, which usually shows up between ages 30 and 60.
  • Researchers studied retinal organoids and retinal pigment epithelium (RPE) cells from patients with CORD21 to understand the gene's role in retinal degeneration.
  • They discovered that DRAM2 is involved in lipid metabolism, lysosomal function, and cellular processes, indicating its importance for the health of photoreceptors and RPE cells.
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Hereditary hemorrhagic telangiectasia (HHT) is a disorder that affects 1 in 5000-10,000 people worldwide and can result in devastating complications such as cerebral abscess, stroke, massive hemorrhage, and even death. HHT is an autosomal dominant disorder that leads to the formation of abnormal communication between the arteries and veins with a resultant spectrum of vascular anomalies. The disorder affects many organ systems and thus requires a dedicated multidisciplinary approach.

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Background: Spinal cerebrospinal fluid venous fistula (CVF) is a recognized cause of chronic positional headache and spontaneous intracranial hypotension (SIH). It occurs due to an aberrant connection formed between the spinal subarachnoid space and an adjacent spinal epidural vein. The diagnosis of CVF can be difficult to establish but can be documented utilizing advanced imaging techniques (e.

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Background: Stent-assisted coiling of wide-necked intracranial aneurysms (IAs) using the Neuroform Atlas Stent System (Atlas) has shown promising results.

Objective: To present the primary efficacy and safety results of the ATLAS Investigational Device Exemption (IDE) trial in a cohort of patients with posterior circulation IAs.

Methods: The ATLAS trial is a prospective, multicenter, single-arm, open-label study of unruptured, wide-necked, IAs treated with the Atlas stent and adjunctive coiling.

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Article Synopsis
  • The study investigates the effectiveness and safety of mechanical thrombectomy in children who have suffered a stroke, aiming to address concerns about inconsistent reporting in existing literature.
  • It compares clinical data from 42 children treated at specific study sites with 133 cases documented in published reports, focusing on the National Institutes of Health Stroke Scale scores before and after treatment.
  • Findings reveal that study site patients had more complete reporting of stroke severity, but they also experienced worse short-term outcomes compared to those reported in literature cases.
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Endovascular thrombectomy has played a major role in advancing adult stroke care and may serve a similar role in pediatric stroke care. However, there is a need to develop better evidence and infrastructure for pediatric stroke care. In this work, we review 2 experienced pediatric endovascular thrombectomy programs and examine key design features in both care environments, including a formalized protocol and workflow, integration with an adult endovascular thrombectomy workflow, simplification and automation of workflow steps, pediatric adaptations of stroke imaging, advocacy of pediatric stroke care, and collaboration between providers, among others.

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Background: Intra-arterial chemotherapy (IAC) represents a mainstay of retinoblastoma treatment in children. Patients with retinoblastoma are uniquely at risk for secondary malignancies and are sensitive to the ionizing effects of radiation.

Objective: To retrospectively review a single institution's experience with IAC for retinoblastoma and the effect of variable intra-procedural imaging techniques on radiation exposure.

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Ophthalmologists are long familiar with the eye showing signs of systemic disease, but the association between age-related macular degeneration and abnormal complement activation, common to several renal disorders, has only recently been elucidated. Although complement activation products were identified in drusen almost three decades ago, it was not until the early 21st century that a single-nucleotide polymorphism in the complement factor H gene was identified as a major heritable determinant of age-related macular degeneration, galvanizing global efforts to unravel the pathogenesis of this common disease. Advances in proteomic analyses and familial aggregation studies have revealed distinctive clinical phenotypes segregated by the functional effects of common and rare genetic variants on the mature protein and its splice variant, factor H-like protein 1.

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We report successful transvenous treatment of direct carotid-cavernous fistula in a patient with Ehlers-Danlos syndrome type IV using a novel triple-overlay embolization (TAILOREd) technique without the need for arterial puncture, which is known to be highly risky in this patient group. The TAILOREd technique allowed for successful treatment using preoperative MR angiography as a three-dimensional overlay roadmap combined with cone beam CT and live fluoroscopy, precluding the need for an arterial puncture.

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Background: Carotid cavernous fistulas (CCF) often present with diplopia secondary to cranial nerve palsy (CNP). Immediate development of postoperative CNP has been described in the literature. This study described delayed-onset of CNP after complete and reconfirmed obliteration of the CCF and resolution of initial CNP.

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Age-related macular degeneration (AMD) is a multifactorial disease, which is characterized by loss of central vision, affecting one in three people by the age of 75. The Y402H polymorphism in the complement factor H (CFH) gene significantly increases the risk of AMD. We show that Y402H-AMD-patient-specific retinal pigment epithelium (RPE) cells are characterized by a significant reduction in the number of melanosomes, an increased number of swollen lysosome-like-vesicles with fragile membranes, Cathepsin D leakage into drusen-like deposits and reduced lysosomal function.

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Background: Nusinersen is the only approved treatment for all spinal muscular atrophy (SMA) subtypes and is delivered intrathecally. Distorted spinal anatomy and instrumentation preclude standard approaches for intrathecal access, necessitating alternative techniques for delivery. The purpose of this study is to report technical success and adverse events of transforaminal intrathecal delivery of nusinersen.

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Introduction: Endovascular embolization of intracranial meningiomas is commonly used as an adjunct to surgical resection. We sought to describe the anatomic locations and vascular supplies of meningiomas to identify characteristics predictive of successful preoperative endovascular embolization.

Methods: We conducted a retrospective review of 139 meningioma cases receiving cerebral angiograms for possible preoperative endovascular embolization at our institution between December 2000 and March 2017.

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Background: Like adults, most children have lifelong morbidity after stroke. Revascularization therapies such as intravenous tissue plasminogen activator and mechanical thrombectomy may be options to decrease this morbidity in selected children, although currently there are no evidence-based recommendations to guide treatment. The utility and safety of mechanical thrombectomy in childhood stroke is unknown because of the lack of safety trials, case-controlled trials, and comprehensive retrospective studies.

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Introduction: Indirect cavernous carotid fistulae (ICCFs) can present with insidious, non-specific symptoms and prove difficult to diagnose. This study evaluates associations among ICCF symptoms and angiographic findings.

Methods: A retrospective analysis was performed of prospectively maintained records at four medical centers to identify patients with ICCFs evaluated with angiography.

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Article Synopsis
  • Tissue-specific extracellular matrices (ECM) support stem cell renewal and differentiation, leading to advancements in tissue engineering through natural ECM scaffolds that closely mimic actual tissues.
  • The study successfully produced decellularised ECM-derived peptides from neural retina and retinal pigment epithelium to improve the differentiation of human pluripotent stem cells into retinal organoids.
  • The addition of these decellularised matrices significantly enhanced the generation of rod photoreceptors and improved synapse formation and light responsiveness, presenting a promising advancement for regenerative medicine applications.
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The scarcity of embryonic/foetal material as a resource for direct study means that there is still limited understanding of human retina development. Here, we present an integrated transcriptome analysis combined with immunohistochemistry in human eye and retinal samples from 4 to 19 post-conception weeks. This analysis reveals three developmental windows with specific gene expression patterns that informed the sequential emergence of retinal cell types and enabled identification of stage-specific cellular and biological processes, and transcriptional regulators.

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Background: Endovascular surgery is the first-line treatment for indirect cavernous carotid fistulae (CCFs). This study compares multiple treatment techniques.

Objective: To compare endovascular techniques for indirect CCF treatment.

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A 59-yr-old woman presented with a sudden onset of headache with neck pain and stiffness, Hunt and Hess grade 2. Brain computed tomography (CT) showed subarachnoid hemorrhage, Fisher Grade 2. Intra-arterial digital subtraction angiography (IADSA) showed a basilar artery apex aneurysm, dome size 9 mm and neck 3 mm, leaning towards the right, and a dominant right artery of Percheron.

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Mutations in pre-mRNA processing factors (PRPFs) cause autosomal-dominant retinitis pigmentosa (RP), but it is unclear why mutations in ubiquitously expressed genes cause non-syndromic retinal disease. Here, we generate transcriptome profiles from RP11 (PRPF31-mutated) patient-derived retinal organoids and retinal pigment epithelium (RPE), as well as Prpf31 mouse tissues, which revealed that disrupted alternative splicing occurred for specific splicing programmes. Mis-splicing of genes encoding pre-mRNA splicing proteins was limited to patient-specific retinal cells and Prpf31 mouse retinae and RPE.

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The prevalence of degenerative retinal disease is ever increasing as life expectancy rises globally. The human retina fails to regenerate and the use of human embryonic stem cells (hESCs) and human-induced pluripotent stem cells (hiPSCs) to engineer retinal tissue is of particular interest due to the limited availability of suitable allogeneic or autologous tissue. Retinal tissue and its development are well characterized, which have resulted in robust assays to assess the development of tissue-engineered retina.

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One of the main challenges in limbal stem cell (LSC) biology and transplantation is the lack of definitive cell surface markers which can be used to identify and enrich viable LSCs. In this study, expression of 361 cell surface proteins was assessed in ex vivo expanded limbal epithelial cells. One marker, CD200 was selected for further characterization based on expression in a small subset of limbal epithelial cells (2.

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The availability of in vitro models of the human retina in which to perform pharmacological and toxicological studies is an urgent and unmet need. An essential step for developing in vitro models of human retina is the ability to generate laminated, physiologically functional, and light-responsive retinal organoids from renewable and patient specific sources. We investigated five different human-induced pluripotent stem cell (iPSC) lines and showed a significant variability in their efficiency to generate retinal organoids.

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Background: Endovascular treatment of intracranial aneurysms is associated with higher rates of recurrence and retreatment, though contemporary rates and risk factors for basilar tip aneurysms (BTAs) are less well-described.

Objective: To characterize progression, retreatement, and retreated progression of BTAs treated with microsurgical or endovascular interventions.

Methods: We retrospectively reviewed records for 141 consecutive BTA patients.

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Objectives: To compare patient factors and outcomes among children admitted to PICUs from referring versus children's hospital emergency departments (EDs).

Methods: Pediatric patients (<19 years old) admitted to PICUs from referring and children's hospital EDs from July 1, 2011 to June 30, 2013. We compared demographic and clinical factors, including severity of illness as measured by a recalibrated Pediatric Index of Mortality, version 2 score.

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